I agree with Genghis, D P Davis' book
'Handling the Big Jets' is a gold mine for really good common sense information. A C Kermode's books are also good,
'The Mechanics of Flight' for example. Also try this website:-
https://www.skybrary.aero/ another good soure of practical information, especially about the relationship between pilots and ATC. And you may find more leads from there to other sources of information. Well done so far, and good luck.